12-110913289-T-C

Position:

• chr12-110913289-T-C

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_000432.4(MYL2):​c.310A>G​(p.Lys104Glu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,894 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: MYL2 NM_000432.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2 O:1
• Conservation: PhyloP100: 7.67

Genes affected

MYL2 (HGNC:7583): (myosin light chain 2) This gene encodes a major sarcomeric protein in mammalian striated muscle. The encoded protein plays a role in embryonic heart muscle structure and function, while phosphorylation of the encoded protein is involved in cardiac myosin cycling kinetics, torsion and function in adults. Mutations in this gene are associated with hypertrophic cardiomyopathy 10 and infant-onset myopathy. [provided by RefSeq, May 2022]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM1: In a chain Myosin regulatory light chain 2, ventricular/cardiac muscle isoform (size 164) in uniprot entity MLRV_HUMAN there are 33 pathogenic changes around while only 3 benign (92%) in NM_000432.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.861

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MYL2	NM_000432.4	c.310A>G	p.Lys104Glu	missense_variant	5/7	ENST00000228841.15	NP_000423.2
MYL2	NM_001406745.1	c.268A>G	p.Lys90Glu	missense_variant	4/6		NP_001393674.1
MYL2	NM_001406916.1	c.253A>G	p.Lys85Glu	missense_variant	5/7		NP_001393845.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MYL2	ENST00000228841.15	c.310A>G	p.Lys104Glu	missense_variant	5/7	1	NM_000432.4	ENSP00000228841.8
MYL2	ENST00000548438.1	c.268A>G	p.Lys90Glu	missense_variant	4/6	3		ENSP00000447154.1
MYL2	ENST00000663220.1	c.253A>G	p.Lys85Glu	missense_variant	5/7			ENSP00000499568.1
MYL2	ENST00000549029.1	n.141A>G		non_coding_transcript_exon_variant	2/2	2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251494 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135922

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461894 Hom.: 0 Cov.: 35 AF XY: 0.00000138 AC XY: 1 AN XY: 727248

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hypertrophic cardiomyopathy 10 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 02, 2024

This sequence change replaces lysine, which is basic and polar, with glutamic acid, which is acidic and polar, at codon 104 of the MYL2 protein (p.Lys104Glu). This variant is present in population databases (rs199474811, gnomAD 0.0009%). This missense change has been observed in individual(s) with hypertrophic cardiomyopathy (PMID: 11748309, 24111713). This variant is also known as Lys103Glu. ClinVar contains an entry for this variant (Variation ID: 31770). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. Experimental studies have shown that this missense change affects MYL2 function (PMID: 24992035, 25770245, 26385864, 33891674). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Nov 21, 2023

This missense variant replaces lysine with glutamic acid at codon 104 of the MYL2 protein. Computational prediction tools indicate that this variant has a deleterious impact on protein structure and function. Functional studies using murine models have shown that this variant causes altered protein function and overall gene expression profiles (PMID: 24992035, 25770245). This variant has been reported in two individuals affected with hypertrophic cardiomyopathy (PMID: 11748309, 24111713); one of these individuals carried a second compound heterozygous intronic MYL2 variant that segregated with disease in the family (PMID: 11748309). This variant has been identified in 1/251494 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

not provided Other:1

not provided, no classification provided

curation

Leiden Muscular Dystrophy (MYL2)

Mar 26, 2012

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.44
CardioboostCm	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.31
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.71	D;.
Eigen	Uncertain	0.47
Eigen_PC	Uncertain	0.49
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.94	D;D
M_CAP	Pathogenic	0.29	D
MetaRNN	Pathogenic	0.86	D;D
MetaSVM	Uncertain	-0.018	T
MutationAssessor	Uncertain	2.0	M;.
PrimateAI	Pathogenic	0.83	D
PROVEAN	Uncertain	-3.4	D;D
REVEL	Pathogenic	0.78
Sift	Uncertain	0.018	D;T
Sift4G	Benign	0.12	T;T
Polyphen		0.86	P;.
Vest4		0.89
MutPred		0.57		Loss of methylation at K104 (P = 0.0042);.;
MVP		0.89
MPC		0.85
ClinPred		0.85	D
GERP RS		5.1
Varity_R		0.68
gMVP		0.86

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs199474811; hg19: chr12-111351093;